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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package com.nulldev.util.graphics.renderIt.ginterfaces.marlin.impl.graphics;

import java.awt.BasicStroke;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.Rectangle2D;

import com.nulldev.util.graphics.renderIt.ginterfaces.marlin.impl.ReentrantContext;
import com.nulldev.util.graphics.renderIt.ginterfaces.marlin.impl.ReentrantContextProvider;
import com.nulldev.util.graphics.renderIt.ginterfaces.marlin.impl.ReentrantContextProviderTL;
import com.nulldev.util.graphics.renderIt.ginterfaces.marlin.impl.pisces.DMarlinRenderingEngine;

import sun.awt.SunHints;
import sun.java2d.SunGraphics2D;
import sun.java2d.pipe.AATileGenerator;
import sun.java2d.pipe.CompositePipe;
import sun.java2d.pipe.ParallelogramPipe;
import sun.java2d.pipe.RenderingEngine;
import sun.java2d.pipe.ShapeDrawPipe;

/**
 * This class is used to convert raw geometry into 8-bit alpha tiles using an
 * AATileGenerator for application by the next stage of the pipeline. This class
 * sets up the Generator and computes the alpha tiles and then passes them on to
 * a CompositePipe object for painting.
 */
public final class AAShapePipe implements ShapeDrawPipe, ParallelogramPipe {

	// Force using Marlin Rendering Engine:
	static final RenderingEngine RDR_ENGINE = new DMarlinRenderingEngine();

	// Per-thread TileState (~1K very small so do not use any Weak Reference)
	private static final ReentrantContextProvider<TileState> TILE_STATE_PROVIDER = new ReentrantContextProviderTL<TileState>(
			ReentrantContextProvider.REF_HARD) {
		@Override
		protected TileState newContext() {
			return new TileState();
		}
	};

	final CompositePipe outpipe;

	public AAShapePipe(CompositePipe pipe) {
		outpipe = pipe;
	}

	@Override
	public void draw(SunGraphics2D sg, Shape s) {
		final BasicStroke bs;

		if (sg.stroke instanceof BasicStroke) {
			bs = (BasicStroke) sg.stroke;
		} else {
			s = sg.stroke.createStrokedShape(s);
			bs = null;
		}

		renderPath(sg, s, bs);
	}

	@Override
	public void fill(SunGraphics2D sg, Shape s) {
		renderPath(sg, s, null);
	}

	@Override
	public void fillParallelogram(SunGraphics2D sg, double ux1, double uy1, double ux2, double uy2, double x, double y, double dx1, double dy1, double dx2,
			double dy2) {
		final TileState ts = TILE_STATE_PROVIDER.acquire();
		try {
			final int[] abox = ts.abox;

			final AATileGenerator aatg = RDR_ENGINE.getAATileGenerator(x, y, dx1, dy1, dx2, dy2, 0, 0, sg.getCompClip(), abox);
			if (aatg != null) {
				renderTiles(sg, ts.computeBBox(ux1, uy1, ux2, uy2), aatg, abox, ts);
			}
		} finally {
			TILE_STATE_PROVIDER.release(ts);
		}
	}

	@Override
	public void drawParallelogram(SunGraphics2D sg, double ux1, double uy1, double ux2, double uy2, double x, double y, double dx1, double dy1, double dx2,
			double dy2, double lw1, double lw2) {
		final TileState ts = TILE_STATE_PROVIDER.acquire();
		try {
			final int[] abox = ts.abox;

			final AATileGenerator aatg = RDR_ENGINE.getAATileGenerator(x, y, dx1, dy1, dx2, dy2, lw1, lw2, sg.getCompClip(), abox);
			if (aatg != null) {
				// Note that bbox is of the original shape, not the wide path.
				// This is appropriate for handing to Paint methods...
				renderTiles(sg, ts.computeBBox(ux1, uy1, ux2, uy2), aatg, abox, ts);
			}
		} finally {
			TILE_STATE_PROVIDER.release(ts);
		}
	}

	public void renderPath(SunGraphics2D sg, Shape s, BasicStroke bs) {
		final boolean adjust = (bs != null && sg.strokeHint != SunHints.INTVAL_STROKE_PURE);
		final boolean thin = (sg.strokeState <= SunGraphics2D.STROKE_THINDASHED);

		final TileState ts = TILE_STATE_PROVIDER.acquire();
		try {
			final int[] abox = ts.abox;

			final AATileGenerator aatg = RDR_ENGINE.getAATileGenerator(s, sg.transform, sg.getCompClip(), bs, thin, adjust, abox);
			if (aatg != null) {
				renderTiles(sg, s, aatg, abox, ts);
			}
		} finally {
			TILE_STATE_PROVIDER.release(ts);
		}
	}

	public void renderTiles(SunGraphics2D sg, Shape s, final AATileGenerator aatg, final int[] abox, final TileState ts) {
		Object context = null;
		try {
			// reentrance: outpipe may also use AAShapePipe:
			context = outpipe.startSequence(sg, s, ts.computeDevBox(abox), abox);

			// copy of int[] abox as local variables for performance:
			final int x0 = abox[0];
			final int y0 = abox[1];
			final int x1 = abox[2];
			final int y1 = abox[3];

			final int tw = aatg.getTileWidth();
			final int th = aatg.getTileHeight();

			// get tile from thread local storage:
			final byte[] alpha = ts.getAlphaTile(tw * th);
			byte[] atile;

			for (int y = y0; y < y1; y += th) {
				final int h = Math.min(th, y1 - y);

				for (int x = x0; x < x1; x += tw) {
					final int w = Math.min(tw, x1 - x);

					final int a = aatg.getTypicalAlpha();

					if (a == 0x00 || !outpipe.needTile(context, x, y, w, h)) {
						aatg.nextTile();
						outpipe.skipTile(context, x, y);
						continue;
					}
					if (a == 0xff) {
						atile = null;
						aatg.nextTile();
					} else {
						atile = alpha;
						// could use w instead of tw (useless padding):
						aatg.getAlpha(alpha, 0, tw);
					}

					// could use w instead of tw (useless padding):
					outpipe.renderPathTile(context, atile, 0, tw, x, y, w, h);
				}
			}
		} finally {
			aatg.dispose();
			if (context != null) {
				outpipe.endSequence(context);
			}
		}
	}

	// Tile state used by AAShapePipe
	static final class TileState extends ReentrantContext {
		// cached tile (32 x 32 tile by default)
		private byte[] theTile = new byte[32 * 32];
		// dirty aabox array
		final int[] abox = new int[4];
		// dirty bbox rectangle
		private final Rectangle dev = new Rectangle();
		// dirty bbox rectangle2D.Double
		private final Rectangle2D.Double bbox2D = new Rectangle2D.Double();

		byte[] getAlphaTile(int len) {
			byte[] t = theTile;
			if (t.length < len) {
				// create a larger tile and may free current theTile (too small)
				theTile = t = new byte[len];
			}
			return t;
		}

		Rectangle computeDevBox(final int[] abox) {
			final Rectangle box = this.dev;
			box.x = abox[0];
			box.y = abox[1];
			box.width = abox[2] - abox[0];
			box.height = abox[3] - abox[1];
			return box;
		}

		Rectangle2D computeBBox(double ux1, double uy1, double ux2, double uy2) {
			if ((ux2 -= ux1) < 0.0) {
				ux1 += ux2;
				ux2 = -ux2;
			}
			if ((uy2 -= uy1) < 0.0) {
				uy1 += uy2;
				uy2 = -uy2;
			}
			final Rectangle2D.Double box = this.bbox2D;
			box.x = ux1;
			box.y = uy1;
			box.width = ux2;
			box.height = uy2;
			return box;
		}
	}
}
